What is the
significance of the terms - ‘isolated gaseous atom’ and
‘ground state’ while defining the ionization enthalpy and
electron gain enthalpy?
Hint: Requirements
for comparison purposes.
What is the significance of the terms - ‘isolated gaseous atom’ and ‘ground state’ while defining the ionization enthalpy and electron gain enthalpy?
Hint: Requirements for comparison purposes.
Ionization enthalpy is
the energy required to remove an electron from an isolated gaseous
atom in its ground state. Although the atoms are widely separated in
the gaseous state, there are some amounts of attractive forces among
the atoms. To determine the ionization enthalpy, it is impossible to
isolate a single atom. But, the force of attraction can be further
reduced by lowering the pressure. For this reason, the term ‘isolated
gaseous atom’ is used in the definition of ionization enthalpy.
Ground state of an atom
refers to the most stable state of an atom. If an isolated gaseous
atom is in its ground state, then less amount energy would be
required to remove an electron from it. Therefore, for comparison
purposes, ionization enthalpy and electron gain enthalpy must be
determined for an ‘isolated gaseous atom’ and its ‘ground
state’.
Ionization enthalpy is the energy required to remove an electron from an isolated gaseous atom in its ground state. Although the atoms are widely separated in the gaseous state, there are some amounts of attractive forces among the atoms. To determine the ionization enthalpy, it is impossible to isolate a single atom. But, the force of attraction can be further reduced by lowering the pressure. For this reason, the term ‘isolated gaseous atom’ is used in the definition of ionization enthalpy.
Ground state of an atom refers to the most stable state of an atom. If an isolated gaseous atom is in its ground state, then less amount energy would be required to remove an electron from it. Therefore, for comparison purposes, ionization enthalpy and electron gain enthalpy must be determined for an ‘isolated gaseous atom’ and its ‘ground state’.
